#include<iostream>
extern double warming;
void updata(double dt);
void local();

using std::cout;
void update(double dt)
{
	extern double warming;
	warming +=dt;
	cout<<"Updating global warming to "<<warming;
	cout<<" degrees.\n";
}

void local()
{
	double warming = 0.8;
	cout<<"Local warming = "<<warming<<" degrees.\n";
	cout<<"But global warming = "<<::warming;
	cout<<" degrees.\n";
}
